Thread: bads vibes and idle td5

Hi All

I have an 03 defender 110 with an issue I cant solve. I have read many posts on this site about similar issues to mine but I hope if I go over it again then you may help me get closer before I throw a load of money at it.

When I start the engine all is well. It idles nice and steady and smooth. When I drive away and come to standstill again often the idle is lumpy. This can be even after 50m or less. Sometimes even any touch of the throttle will see it go bad. when i drive away all is smooth again. Often a bit gutless but then all of a sudden its off. When it idles it always goes smooth then rough then smooth over and over

When I slow down from speed with my foot on the clutch but not yet stopped it goes odd. sounds like its missing but I get the feeling its adding fuel not actually missing. When I stop it comes right after a second of two. The idle then is sometimes quite good but other times still idles rough. Other times it just pull up like normal.

When I rev the engine it will vibrate at around 2300-3000rpm in every gear. If you push past this then it will rev smooth again. I get then feeling its still actually doing it but but the engine speed smooths it out as it feels lethargic at these revs. I can replicate this when stationary and when I do this it will also shudder at about 2500 if you hold it there. Any sudden backing off of the throttle will do this as well. Hard to tell but I think it is less pronounced with the clutch in rather than just in neutral.

Every now and then it will be fine and rev right through the rough spot smoothly. I do feel it has more power when this happens.

- I have replaced the engine wiring harness. It was stuffed and dripping with oil. I cleaned out the harness at the computer and the oil seems to have stopped.
- The waste-gate is no longer jammed.
- I have cleaned the MAF and manifold sensors. Not to say they are not buggered though.
- The crankshaft pulley has a little play but not much.
It uses no oil or water.
It does not collect diesel in the oil.

Ive read chapter after chapter on this issue some seem to be similar others less so I dont want to just do what others did all the time in case its a different problem. The ones that seem the same have no explanation either.

What do you reckon, any help is much appreciated

Cheers

Right. I have a theory. It seems that everything that can go wrong with a td5, in some way manifests itseslf as a vibration at 2500, that just seems to be a characteristic of the 5cyl motor.
IF ITS NOT RUNNING DEAD RIGHT IN ANY WAY THIS IS WHAT IT WILL DO!.However it makes it bloody hard to diagnose what wrong as this always seems to be one of the symptoms, especially if you have multiple issues.

I am however uncovering some of the vibrations as they each have subtle quirks (in my case anyway).

I cleaned out the airfilter, went a bit better, still vibes
I got rid of the hiclone thing, went even better still, still vibes may even have been worse. so i figured load was an issue or more air made it bad.
I changed the MAF with one out of a mates td5 that I knew went really well.
Heaps bloody better. half the vibes gone. more power revs out well. more torque. idles smooth and steady. Loads of vibes still, though less harsh. the remaining vibes I'm fairly sure are to do with the flywheel. its a heavy feeling vibe not a harshness as before. and there is certainly an exhaust resonance of some sort. I may or maynnot fix these as the car is much more liveable than before. I far prefered my 300tdi to drive as it was much smoother but the td5 is redeaming itself slowly.